WDPN31 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 24W (YINXING) WARNING NR 
034//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.7N 110.2E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 111 NM EAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 11 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED SHORTWAVE INFRARED SATELLITE IMAGERY AND AN 111052Z SSMIS
91GHZ MICROWAVE IMAGE DEPICT AN EXPOSED, DEFINED LOW-LEVEL 
CIRCULATION CENTER WITH DEEP CONVECTIVE BANDING OVER THE NORTHWEST 
QUADRANT. ENVIRONMENTAL CONDITIONS CONTINUE TO DEGRADE, WITH LOW TO 
MODERATE VERTICAL WIND SHEAR, EXTENSIVE DRY AIR AND MARGINAL SST 
VALUES. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED 
ON THE SATELLITE IMAGERY. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED 
WITH HIGH CONFIDENCE BASED ON AN AVERAGE OF THE AGENCY DVORAK 
ESTIMATES, CONSISTENT WITH THE WEAKENED CONVECTIVE STRUCTURE.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: LOW-LEVEL SUBTROPICAL RIDGE (STR)
POSITIONED TO THE NORTH OVER SOUTHERN CHINA.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS SATCON: 47 KTS AT 111055Z
   CIMSS ADT: 41 KTS AT 111130Z
   CIMSS AIDT: 37 KTS AT 111130Z
   CIMSS D-MINT: 30 KTS AT 111054Z
   CIMSS D-PRINT: 28 KTS AT 111200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 15-20 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD
   OTHER FACTORS: EXTENSIVE DRY AIR

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL STORM (TS) 24W WILL TRACK QUICKLY
SOUTH-SOUTHWESTWARD ALONG THE PERIPHERY OF THE LOW-LEVEL STR MAKING
LANDFALL NEAR TAU 12. AFTER TAU 12, THE SYSTEM WILL RAPIDLY
DISSIPATE OVER LAND. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN FAIR
AGREEMENT, WITH A 50NM CROSS-TRACK SPREAD AT LANDFALL NEAR TAU 12.
PROBABILISTIC GUIDANCE ALSO INDICATES MEDIUM CONFIDENCE IN THE JTWC
TRACK FORECAST AND HIGH CONFIDENCE IN THE JTWC INTENSITY FORECAST.
RELIABLE INTENSITY GUIDANCE SUPPORTS THE RAPID WEAKENING OF THE
SYSTEM.  

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   INTENSITY 0 - 72 HR: HIGH//
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